中文摘要：

污水和再生水灌溉在我国北方地区十分普遍,由于长期灌溉导致土壤中遗传毒性物质累积并因此而引发的生态安全问题值得研究。本研究利用离体umu/SOS测试与活体蚯蚓彗星试验评价北京市郊区再生水灌溉土壤中遗传毒性物质的积累。umu/SOS测试得到表征样品遗传毒性大小的β-半乳糖苷酶诱导活性（IU值）,以达到阳性时（诱导比率R=2）需要的土壤重量（G）来反映土壤样品的相对遗传毒性。活体蚯蚓彗星试验中,以尾矩（TM）表征土壤遗传毒性的大小。研究结果表明,再生水灌溉使得土壤的遗传毒性增大,随着再生水灌溉量的增加,土壤的G值减小,TM值增大,G值与TM值之间呈现明显相关关系,说明主要遗传毒性物质是有机污染物。离体umu/SOS测试和活体蚯蚓彗星试验的联合应用,可以快速有效地筛选出遗传毒性高风险土壤样品。

英文摘要：

Soil irrigation with wastewater and reclaimed water is a common practice in North China. Its potential ecological risk of accumulation of genotoxic substances is a major concern worth studying. In this paper, in vitro umu/SOS test and in vivo Comet assay were used to assess accumulation of genotoxic substances in the soil irrigated with reclaimed water in suburbs of Beijing. Relative genotoxicity was determined by weight of the soil （G） needed to show positive （or to reach 2 in induction ratio R）, and Tail Moment （TM） was cited in Comet assay to characterize genotoxicity of the soil. Results showed G decreased and TM increased along with the increase in amount of reclaimed water used in irrigation, implying that the use of reclaimed water in irrigation could result in increase in genotoxicity of the soil. A significant relationship was observed between G and TM, suggesting that genotoxic substances in the soil irrigated with reclaimed water are mainly organic contaminants. It could be concluded that the umu/SOS test combining with the Comet assay could be used to screen out high risk soil samples rapidly and effectively.